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    (Original post by AS01)
    hey! how u doing? feeling prepared for this unit?
    Not sitting it :P
    Will be doing Chemistry Unit 5 next Wednesday though!
    I came to wish you all good luck as Unit 4 is my favourite Unit, but I think I'm unpopular in this opinion
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    (Original post by posthumus)
    Also did I need to remember persulfate ?

    A possibility But I thought maybe you could look in the data booklet, and I think you can look at the dissociation constants & compared.... that's if your really stuck I think it'll be obvious from there but I've never tried it.

    & I'm not sure if your right Steamy fumes is for HCl... but I think NH4Cl is white "smoke"

    And yes please I will be going to sleep by 12 though I am worrying too much... I hope I get sleep

    Explain to me in terms of kinetic/heat energy.... why exothermic reactions have positive entropy surroundings and also usually negative entropy of systems
    oh yeah! u did stay excess ammonia! so yeah white smoke
    no u dont have to remember about persulphate but there are others too even haber process and contact process are example of heterogenous catalyst

    they give off heat so increase in kinetic energy of molecules in air increase in disorder not sure about the system
    how can u distinguish between CHO and RCOR? give both tests
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    (Original post by Mollymod)
    Not sitting it :P
    Will be doing Chemistry Unit 5 next Wednesday though!
    I came to wish you all good luck as Unit 4 is my favourite Unit, but I think I'm unpopular in this opinion
    lucky you! what did u get?
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    (Original post by AS01)
    oh yeah! u did stay excess ammonia! so yeah white smoke
    no u dont have to remember about persulphate but there are others too even haber process and contact process are example of heterogenous catalyst

    they give off heat so increase in kinetic energy of molecules in air increase in disorder not sure about the system
    how can u distinguish between CHO and RCOR? give both tests
    that's a relief !!!

    Hehe, well if kinetic/heat energy being lost by the system then I'm sure molecules will behave themselves more and become more ordered

    Hmmmmm Aldehyde will give silver mirror with tollens reagant & Red precipitate with Fehlings

    + you can use brady's reagant

    (before you say I'm wrong... you then filter off the precipitate add minimum hot ethanol then leave it recrystallize Then check melting temp)

    Explain to me how Iodine clock works !
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    Please tell me how is the ans C?
    Its june 2011 q6 :hmpf:

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    (Original post by posthumus)
    that's a relief !!!

    Hehe, well if kinetic/heat energy being lost by the system then I'm sure molecules will behave themselves more and become more ordered

    Hmmmmm Aldehyde will give silver mirror with tollens reagant & Red precipitate with Fehlings

    + you can use brady's reagant

    (before you say I'm wrong... you then filter off the precipitate add minimum hot ethanol then leave it recrystallize Then check melting temp)

    Explain to me how Iodine clock works !
    lol finally u got the tests name right!
    u mix the reactant and record time taken to make specific amount of product

    why is acyl chloride more reactive than amide for addition elimination rxn?
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    (Original post by AS01)
    lucky you! what did u get?
    A middle B :P
    Not really bothered, as I retook Unit 1 and have good A2 practicals.
    Goodluck with this! Not sure that you'll need it though :P
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    (Original post by AT95)
    Please tell me how is the ans C?
    Its june 2011 q6 :hmpf:

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    methanoic acid methanol ester water
    4 6 0 0
    4-3=1 6-3=1 3 3
    eqm conc is those moles divide by V which will cancel as there are equal moles at the top and at the bottom
    so Kc= 3
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    (Original post by Mollymod)
    A middle B :P
    Not really bothered, as I retook Unit 1 and have good A2 practicals.
    Goodluck with this! Not sure that you'll need it though :P
    lol I sure do! thanks a lot! Hopefully the paper is good
    what grade do u need for chem?
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    (Original post by AS01)
    lol finally u got the tests name right!
    u mix the reactant and record time taken to make specific amount of product

    why is acyl chloride more reactive than amide for addition elimination rxn?
    We don't need to know which reagents you pit in... like peroxide KI starch..?

    Erm I never knew amides underwent addition elimination & electroneg Cl- + oxygen are pulling electrons away from carbon.. this makes it very delta +. Also Cl- is a very good leaving group & The C-Cl bond is very weak

    ketone + LiAlH4 ... describe the process
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    (Original post by AT95)
    Please tell me how is the ans C?
    Its june 2011 q6 :hmpf:

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    I got stuck on this tooo.... H2O is a product...

    subtract 3 from the reactants & then use the formula (ignore dividing by volume)
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    (Original post by posthumus)
    We don't need to know which reagents you pit in... like peroxide KI starch..?

    Erm I never knew amides underwent addition elimination & electroneg Cl- + oxygen are pulling electrons away from carbon.. this makes it very delta +. Also Cl- is a very good leaving group & The C-Cl bond is very weak

    ketone + LiAlH4 ... describe the process
    lol hopefully we dont and yeah ur answer is right
    dont think we need to know the process though
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    (Original post by Mollymod)
    Love Unit 4!
    You guys will be great
    Thanks mollymod Hope unit 5 revision is going well! (and from what I've seen - your doing frickin' awesome )
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    (Original post by AS01)
    lol hopefully we dont and yeah ur answer is right
    dont think we need to know the process though
    There's so much we don't need to know lol :eek: (Damn george :mad: )

    I have far less time this time for unit 5.... so I might abandon george and just use revision guides..

    Well anyway I am off to get some sleep now

    Good luck AS01 with your exam tomorrow... & speak to ya soon Thanks for all the questions also you've asked me (I have learnt a lot, imagine brady's came up tomorrow )

    And good luck to everyone else too who reads this ! May speak to some of you tomorrow morning
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    (Original post by posthumus)
    There's so much we don't need to know lol :eek: (Damn george :mad: )

    I have far less time this time for unit 5.... so I might abandon george and just use revision guides..

    Well anyway I am off to get some sleep now

    Good luck AS01 with your exam tomorrow... & speak to ya soon Thanks for all the questions also you've asked me (I have learnt a lot, imagine brady's came up tomorrow )

    And good luck to everyone else too who reads this ! May speak to some of you tomorrow morning
    lol we dont
    Good luck to you too! you asked me far better questions than I did
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    im in sri lanka.. i got 3 more hours till the exam.. :P anybody here? wanna revise sum stuff? :P
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    (Original post by Amila888)
    im in sri lanka.. i got 3 more hours till the exam.. :P anybody here? wanna revise sum stuff? :P
    What time is your exam?:eek: Our exam starts at 5.. I'm tempted to ask you what will pop up in the exam now haha
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    (Original post by AT95)
    What time is your exam?:eek: Our exam starts at 5.. I'm tempted to ask you what will pop up in the exam now haha
    ooops.. i got the time wrong. its at 5.30pm local time. i was thinking 1.30.!!!.
    so i got 6 hours i guess
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    (Original post by Amila888)
    ooops.. i got the time wrong. its at 5.30pm local time. i was thinking 1.30.!!!.
    so i got 6 hours i guess
    Oh lol then we have it at the same time almost :cool:

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    (Original post by AT95)
    Oh lol then we have it at the same time almost :cool:

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    haha... so which past paper did u find most difficult? i found Jan 2010 quite tricky !

    u also got any model papers ??
 
 
 
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